What would Darwin think about clean-slate architectures?

As significant resources are directed towards clean-slate networking research, it is imperative to understand how clean-slate architectural research compares to the diametrically opposite paradigm of evolutionary research. This paper approaches the "evolution versus clean-slate" debate through a biological metaphor. We argue that evolutionary research can lead to less costly (more competitive) and more robust designs than clean-slate architectural research. We also argue that the Internet architecture is not ossified, as recently claimed, but that its core protocols play the role of "evolutionary kernels", meaning that they are conserved so that complexity and diversity can emerge at the lower and higher layers. We then discuss the factors that determine the deployment of new architectures or protocols, and argue, based on the notion of "auto-catalytic sets", that successful innovations are those that become synergistic components in closed loops of existing modules. The paper closes emphasizing the role of evolutionary Internet research.